JP6257263B2 - Image forming apparatus - Google Patents

Description

The present invention is a copying machine using an electrophotographic method or an electrostatic recording method, a printer, it relates to an image forming equipment such as a facsimile apparatus.

  Conventionally, in an image forming apparatus using, for example, an electrophotographic method, the surface of an electrophotographic photosensitive member (photosensitive member) as a member to be charged is charged with a charger, and then the surface of the charged photosensitive member is exposed according to image information. As a result, an electrostatic latent image is formed on the surface of the photoreceptor. As a charger for charging the surface of the photoreceptor, a corona discharger (corona discharge generator) is widely used.

  In general, a corona discharger is provided with support blocks at both ends of a shield case serving as a support housing with one side open, and a discharge wire made of a metal wire such as tungsten is interposed between the support blocks. It is extended. When charging a charged surface of a charged member such as a photoconductor using a corona discharger, the open surface of the shield case is opposed to the charged surface in a close state, and a discharge current is supplied to the discharge line to cause corona discharge. The charge is applied to the surface to be charged. In addition, a grid is provided between the discharge line and the surface to be charged on the open surface of the shield case, and the amount of charge applied to the surface to be charged is adjusted by applying a grid bias to the grid so that the charged potential of the surface to be charged It is also done to control.

  When contaminants such as toner, external additives, or paper dust adhere to the discharge lines and grid of the corona discharger, unevenness (charged spots) in the potential distribution in the longitudinal direction of the surface to be charged (longitudinal direction of the corona discharger) May occur and image defects may occur. Therefore, the corona discharger may be provided with a cleaning member for cleaning the discharge lines and the grid. For example, the contaminant attached to the discharge line or the grid is removed by moving the cleaning member along the shield case in the longitudinal direction of the corona discharger (reciprocating motion or the like).

  Incidentally, in the image forming apparatus, when the image forming unit is detachable from the apparatus main body, it is required to stably support the image forming unit with respect to the apparatus main body in the mounted state. If this support state is unstable, for example, an image defect called banding may occur. Banding refers to periodic density unevenness in the sub-scanning direction that occurs on an image. This is because the image forming unit having the photosensitive member vibrates to cause a shift in the image writing position, the image transfer position, and the like. In view of this, Japanese Patent Laid-Open No. 2004-228688 discloses that vibration is prevented by providing a pressing member between image forming units in order to suppress banding.

  Further, for example, when a corona discharger is used as a charger for charging the surface of the photosensitive member and the corona discharger itself is detachable from the apparatus main body, the density on the image depends on the support state of the corona discharger. Unevenness may occur. This is because the vibration from the vibration source in the main body of the apparatus is transmitted to vibrate the corona discharger, and the distance between the photoconductor and the corona discharger fluctuates, resulting in potential unevenness. Therefore, it is conceivable to suppress the vibration of the corona discharger by means such as bringing the pressing member as described above into contact.

JP 11-316537 A

  However, when the corona discharger is pressed by the pressing member, the shield case of the corona discharger may be deformed. If the shield case or the like of the corona discharger is deformed, for example, when a discharge member or a grid cleaning member that moves along the shield case is provided as described above, the movement is hindered. Sometimes.

  In the above, the conventional problem has been described in detail for the case where the corona discharger is a charger for charging the surface of the photoreceptor, but the corona discharger may be used for other purposes in the image forming apparatus. For example, the corona discharger is also used as a static eliminating unit that neutralizes the surface of an image carrier such as a photoconductor, or a transfer unit that transfers a toner image from an image carrier such as a photoconductor to a transfer target. In any of these applications, it is a problem to deform the corona discharger.

An object of the present invention, a corona discharger, while suppressing undesirable deformation is to provide an image forming equipment which makes it possible to stably supported.

The above object is manually achieved in the image forming equipment according to the present invention. In summary, in the image forming apparatus , the present invention provides a photoconductor, a corona discharger for charging the photoconductor, a discharge electrode disposed along a longitudinal direction of the corona discharger, and the longitudinal direction. A first shield plate and a second shield plate disposed opposite to each other with the discharge electrode interposed therebetween, and formed between the first shield plate and the second shield plate on one surface A housing having an opening to be cleaned, a cleaning member that cleans the portion to be cleaned by moving while abutting against the portion to be cleaned of the corona discharger, and a member that holds the cleaning member and moves in the longitudinal direction A holding member, and a corona discharger that is attachable to and detachable from an apparatus main body of the image forming apparatus, and a mounting portion on which the corona discharger is mounted with the opening facing the photoreceptor. A corona discharger belts the photoreceptor. A first pressing member that presses the first shield plate toward the second shield plate in a state where the first shield plate is mounted on the charging position, and the corona discharger is mounted on the charging position. A second pressing member that presses the second shield plate toward the first shield plate, and a third pressing member, and the second pressing member in the longitudinal direction. Each position where the third pressing member presses the second shield plate is a position on one end side with respect to a position where the first pressing member presses the first shield plate. The image forming apparatus is arranged at a position on the other end side .

  According to the present invention, the corona discharger can be stably supported while suppressing undesirable deformation.

1 is a schematic cross-sectional view of an image forming apparatus. It is sectional drawing of a charger and its mounting part. It is a top view of a charger and its mounting part. It is a perspective view of the drive structure of the cleaning member in a charger. It is explanatory drawing of operation | movement at the time of inserting a charging device in the mounting part of an apparatus main body.

Hereinafter will be described in more detail with reference to an image forming equipment according to the present invention with reference to the drawings.

Example 1
1. FIG. 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 100 according to the present exemplary embodiment is a tandem type image forming apparatus that employs an intermediate transfer method capable of forming a full-color image.

  The image forming apparatus 100 includes first, second, third, and fourth image forming units 1Y, 1M, 1C, and 1K that are arranged in series along a horizontal portion of an intermediate transfer belt 31 described later. Each of the image forming units 1Y, 1M, 1C, and 1K uses each color of yellow (Y), magenta (M), cyan (C), and black (K) by an electrophotographic method in accordance with an image signal transmitted from an external device. The toner image is formed.

  In this embodiment, the configurations and operations of the image forming units 1Y, 1M, 1C, and 1K are substantially the same except that the color of the toner to be used is different. Therefore, in the following, unless there is a particular need to distinguish, the Y, M, C, and K at the end of the symbol indicating that the element is provided for any color will be omitted, and the element will be described comprehensively. To do.

  The image forming unit 1 includes a photosensitive drum 11 that is a drum-type (cylindrical) electrophotographic photosensitive member (photosensitive member) as an image carrier. The photosensitive drum 11 is rotationally driven in the direction of arrow R1 in the figure. Around the photosensitive drum 11, the following units are arranged along the rotation direction. First, a charger 12 composed of a corona discharger as a charging means is disposed. Next, an exposure device 13 as an exposure unit is arranged. Next, a developing device 14 as a developing unit is disposed. Next, a primary transfer roller 35 which is a roller-shaped primary transfer member as a primary transfer unit is disposed. Next, a cleaning device 15 as a photosensitive member cleaning unit is disposed.

  Further, an intermediate transfer belt 31 constituted by an endless belt as an intermediate transfer member is disposed so as to face the photosensitive drums 11Y, 11M, 11C, and 11K of the image forming units 1Y, 1M, 1C, and 1K. ing. The intermediate transfer belt 31 is stretched around a driving roller 33, a tension roller 34, and a secondary transfer counter roller 32. When the driving roller 33 is driven to rotate, the intermediate transfer belt 31 rotates (circulates) in the direction of arrow R2 in the figure. On the inner peripheral surface side of the intermediate transfer belt 31, the primary transfer rollers 35Y, 35M, 35C, and 35K are disposed at positions facing the photosensitive drums 11Y, 11M, 11C, and 11K. The primary transfer roller 35 is urged (pressed) toward the photosensitive drum 11 via the intermediate transfer belt 31 to form a primary transfer portion N1 where the intermediate transfer belt 31 and the photosensitive drum 11 are in contact with each other. Further, on the outer peripheral surface side of the intermediate transfer belt 31, a secondary transfer roller 41 that is a roller-like secondary transfer member as a secondary transfer unit is disposed at a position facing the secondary transfer counter roller 32. The secondary transfer roller 41 is urged (pressed) toward the secondary transfer counter roller 32 via the intermediate transfer belt 31, and the secondary transfer portion where the intermediate transfer belt 31 and the secondary transfer roller 41 come into contact with each other. N2 is formed. Further, on the outer peripheral surface side of the intermediate transfer belt 31, a belt cleaning device 36 as an intermediate transfer member cleaning unit is disposed at a position facing the driving roller 33.

  In addition, the image forming apparatus 100 includes a feeding unit that feeds the recording material S to the secondary transfer unit N2, a fixing unit that fixes the toner image to the recording material S, and the like.

  At the time of image formation, the photosensitive drum 11 is rotationally driven, and the surface of the rotating photosensitive drum 11 is charged substantially uniformly by the charger 12. The surface of the charged photosensitive drum 11 is irradiated with image light corresponding to the image information by an exposure device (laser scanner device) 13 to form an electrostatic latent image (electrostatic image) corresponding to the image information. The electrostatic latent image formed on the photosensitive drum 11 is developed (visualized) as a toner image by transferring toner as a developer by the developing device 14. The toner image formed on the photosensitive drum 11 is electrostatically transferred (primary transfer) onto the intermediate transfer belt 31 by the action of the primary transfer roller 35 in the primary transfer portion N1. For example, when a full-color image is formed, the toner images of the respective colors formed on the photosensitive drums 11Y, 11M, 11C, and 11K by the operation as described above are sequentially superimposed on the same image position on the intermediate transfer belt 31. Is transcribed.

  On the other hand, a recording material (sheet material) S such as recording paper stored in the paper feed cassettes 61, 62, 63, 64 is fed and conveyed when one of the paper feed rollers 71, 72, 73, 74 rotates. It is conveyed to the path 81. The recording material S is fed by the registration roller 75 to the secondary transfer portion N2 in synchronization with the toner image on the intermediate transfer belt 31. The toner image on the intermediate transfer belt 31 is electrostatically transferred (secondary transfer) onto the recording material S by the action of the secondary transfer roller 41 in the secondary transfer portion N2.

  The recording material S to which the toner image has been transferred is transported to a heat fixing device 5 as a fixing means by a transport belt 42, where the toner image is fixed on the surface by being heated and pressed. The recording material S on which the toner image has been fixed in this manner is then sent out to the paper discharge tray 65 through the paper discharge conveyance path 82.

  The toner remaining on the photosensitive drum 11 after the primary transfer (primary transfer residual toner) is removed from the photosensitive drum 11 by the cleaning device 15 and collected. Further, the toner remaining on the intermediate transfer belt 31 after the secondary transfer (secondary transfer residual toner) is removed from the intermediate transfer belt 31 by the belt cleaning device 36 and collected.

2. Next, the charger 12 in this embodiment will be described. In the following description, with respect to the elements of the image forming apparatus 100 such as the image forming apparatus 100 or the charger 12, the front side of the sheet of FIG. The depth direction connecting the front side and the rear side is substantially parallel to the longitudinal direction (rotational axis direction) of the photosensitive drum 11.

  2 is a cross-sectional view of the charger 12 as viewed from the front side, and FIG. 3 is a top view of the charger 12 with the front side on the left side of the drawing. 2 and 3 also show the mounting portion 3 of the charger 12 in the apparatus main body 2 of the image forming apparatus 100 described later in detail.

  In this embodiment, the charger 12 for charging the surface (charged surface) of the photosensitive drum (charged member) 11 is constituted by a corona discharger (corona discharge generator), particularly a scorotron. The charger 12 is provided with support blocks 129a and 129b at both ends of a shield case 123 as a case that is a support case open on one side, and a discharge electrode as a discharge electrode is provided between the support blocks 129a and 129b. An electric wire 122 is extended. A grid 121 is provided between the discharge line 122 and the photosensitive drum 11 on the open surface 123 g as an opening of the shield case 123. In the charger 12, the open surface 123 g side of the shield case 123, that is, the side on which the grid 121 is provided is opposed to the surface of the photosensitive drum 11 in a close state.

  More specifically, the discharge line 122 is disposed along the longitudinal direction (axial direction) of the charger 12 disposed substantially parallel to the longitudinal direction of the photosensitive drum 11 (substantially parallel in this embodiment). The discharge line 122 is connected to a high voltage power source (not shown). The discharge line 122 generates a corona discharge when a discharge bias is applied from the high-voltage power supply. As the discharge wire 122, a metal wire material such as stainless steel, nickel, molybdenum, tungsten, or the like can be suitably used. In this embodiment, a tungsten wire having high stability among metals is used as the discharge wire 122. The diameter of the discharge line 122 is preferably 40 μm to 100 μm. This is because if the diameter is too small, it tends to break due to ion collision caused by discharge, and conversely if the diameter is too large, a larger applied voltage is required to obtain a stable corona discharge. In this embodiment, the diameter of the discharge line 122 is 50 μm.

  The shield case 123 includes side shield plates 123 a and 123 b that are disposed along the longitudinal direction of the charger 12 at positions facing each other with the discharge wire 122 interposed therebetween. The shield case 123 has a top shield plate 123c disposed along the longitudinal direction of the charger 12 at a position facing the photosensitive drum 11 (grid 121) with the discharge wire 122 interposed therebetween. The surface facing the top shield plate 123c of the shield case 123 is an open surface 123g. As for the side shield plates 123a and 123b, the left shield plate 123a is disposed on the left side when viewed from the front side, and the right shield plate 123b is disposed on the right side. In the present embodiment, the side shield plates 123a and 123b and the top shield plate 123c are integrally formed. The top shield 123c is provided with a through hole 123d so that a cleaning member holding member to be described later can be moved. Thus, the shield case 123 is disposed so as to surround the discharge line 122 except for one surface on the photosensitive drum 11 side. The shield case 123 is made of metal and is electrically grounded.

  The grid 121 is a metal plate-like member, and is disposed on the open surface (opening) 123 g of the shield case 123 on the photosensitive drum 11 side. The grid 121 has a porous shape (mesh shape or slit shape) in which a plurality of apertures penetrating the side facing the photosensitive drum 11 and the side facing the discharge line 122 are formed. The grid 121 is connected to a constant voltage power source (not shown). Then, by controlling the grid bias applied to the grid 121 from this constant voltage power source, the charge generated by the discharge line 122 is rectified, and the amount of charge applied to the photosensitive drum 11 is adjusted.

  In this embodiment, the charger 12 includes a cleaning pad 124 that is a cleaning member that cleans the discharge lines 122 and a cleaning brush 127 that is a cleaning member that cleans the grid 121. The cleaning pad 124 is held by a cleaning pad holding member 125, and the cleaning brush 127 is held by a cleaning brush holding member 128. The cleaning pad 124 has two parts, a first part 124a and a second part 124b, each formed of a sponge with a nonwoven fabric attached to the surface thereof. The cleaning pad 124 is in contact with the discharge line 122 so as to be sandwiched between the two portions 124a and 124b. Further, the cleaning brush 127 is configured by weaving an acrylic brush into a base material, and is in contact with the grid 121 having an opening.

  FIG. 4 is a perspective view of the charger 12 showing the drive configuration of the cleaning member in the present embodiment. The cleaning pad holding member 125 is held so as to be movable in the longitudinal direction of the charger 12 using the shield case 123 as a rail. More specifically, in this embodiment, a fitting groove 123e is formed on the left shield plate 123a on the side opposite to the photosensitive drum 11. The fitting groove 123e may be formed integrally with the left shield plate 123a, or may be provided by connecting a separate member from the left shield plate 123a. Further, the side of the right shield plate 123b opposite to the photosensitive drum 11 is bent, and a rail surface 123f is formed on the upper surface thereof. In the cleaning pad holding member 125, a support receiving portion 125a formed at one end in a direction intersecting with the moving direction (substantially orthogonal in the present embodiment) is disposed in the fitting groove 123e, and the other in the same direction is arranged. A support receiving portion 125b formed at the end is disposed on the rail surface 123f. The cleaning pad 124 is held by the pad holding part 125c provided on the discharge line 122 side between the support receiving parts 125a and 125b, and the drive receiving part 125d provided on the opposite side of the discharge line 122 is provided with the screw 126. Is engaged.

  The screw 126 is arranged such that its longitudinal direction (rotation axis direction) is substantially parallel to the longitudinal direction of the charger 12, and a screw gear 133 is fixed to one end portion (front side) of the longitudinal direction. Yes. The screw gear 133 is engaged with a motor gear 132 fixed to a drive shaft (output shaft) of a drive motor 131 as a drive source. Accordingly, by rotating the drive motor 131, the screw 126 can be rotated via the motor gear 132 and the screw gear 133, and the cleaning pad holding member 125 can be moved along the longitudinal direction of the charger 12. Further, since the cleaning brush holding member 128 is connected to the cleaning pad holding member 125, the cleaning brush holding member 128 can be moved simultaneously by moving the cleaning pad holding member 125. Note that, by switching between forward rotation and reverse rotation of the drive motor 131, the moving direction of the cleaning pad holding member 125 and the cleaning brush holding member 128 can be switched between the forward direction and the backward direction. In this way, the cleaning pad 124 and the cleaning brush 127 as the moving members can be reciprocated in the longitudinal direction of the charger 12 along the shield plates 123a and 123b.

3. Anti-Vibration Configuration Next, the anti-vibration configuration of the charger 12 in this embodiment will be described.

  The charger 12 is attached to the attachment portion 3 provided in the apparatus main body 2 of the image forming apparatus 100. The mounting portion 3 includes a left rail 16 disposed on the left side of the charger 12 as viewed from the front side, and a right rail 17 disposed on the right side. The charger 12 is disposed between the left rail 16 and the right rail 17.

  In the present embodiment, the left rail 16 is provided with a first pressing member 18a as a first pressing means between the left shield plate 123a. Further, the right rail 17 is provided with second and third pressing members 18b and 18c as second and third pressing means between the right shield plate 123b. As a result, the charger 12 is sandwiched between the left rail 16 and the right rail 17 via the first, second, and third pressing members 18a, 18b, and 18c.

  The first, second, and third pressing members 18 a, 18 b, and 18 c press the shield case 123 of the charger 12 in the direction intersecting the longitudinal direction of the charger 12 in the mounting portion 3. Here, the first pressing member 18a and the second and third pressing members 18b and 18c press the shield case 123 of the charger 12 from the opposite sides. The second and third pressing members 18b and 18c are shielded from the first pressing member 18a on the one end side and the other end side in the longitudinal direction of the charger 12, respectively. Press. In particular, in the present embodiment, the first pressing member 18 a presses the shield case 123 of the charger 12 at a substantially central portion in the longitudinal direction of the charger 12. Further, in the present embodiment, the second and third pressing members 18b and 18c are shielded by the shielding case 123 of the charger 12 at positions that are substantially the same distance from the first pressing member 18a in the longitudinal direction of the charger 12, respectively. Press.

  As described above, the first pressing member 18 a is provided on the left rail 16 at a position corresponding to the central portion in the longitudinal direction of the charger 12. Further, second and third pressing members 18b and 18c are provided on the right rail 17 at positions corresponding to both ends of the charger 12 in the longitudinal direction. The first pressing member 18a and the second and third pressing members 18b and 18c press the left shield plate 123a and the right shield plate 123b of the charger 12, respectively. Thereby, the charger 12 is fixed in a vibration-proof manner.

  In this embodiment, a metal leaf spring is used as the pressing member 18 (18a, 18b, 18c). However, the present invention is not limited to this, and an elastic body such as a sponge may be used.

  More specifically, as a vibration isolating structure of the charger 12, it is desirable to hold the charger 12 from the left and right with the pressing member 18. At this time, due to the nature of the shield case 123, which is a support housing with one side opened as in this embodiment, it is easy to obtain a vibration-proofing effect, particularly when pressed at the center in the longitudinal direction. However, when both of the pressing members 18 that press the charger 12 from the left and right are arranged in the central portion in the longitudinal direction, the rail portions (fitting grooves 123e) of the shield plates 123a and 123b that support the cleaning pad holding member 125. The rail surface 123f) may be deformed. For example, the distance between the rails may be reduced at the central portion in the longitudinal direction, which may impede driving of the cleaning pad holding member 125.

  Therefore, in this embodiment, a total of three pressing members 18 (one at the left and right of the charger 12, one at the center in the longitudinal direction of the charger 12, and two at both ends in the longitudinal direction of the charger 12 in total. 18a, 18b, 18c) holds the charger 12. As a result, it is possible to isolate the charger 12 while suppressing the deformation as described above.

Here, as the balance of the pressing force of the three pressing members 18 (18a, 18b, 18c), from the balance of force and moment,
First pressing member 18a: Second pressing member 18b: Third pressing member 18c
= 2: 1: 1
Is desirable. In the case where the relationship deviates significantly from this relationship, for example, when a positioning shaft for supporting the charger 12 is provided in addition to the pressing member 18 (18a, 18b, 18c), an extra load is applied to the support portion of the positioning shaft. Will cause deformation. In the present embodiment, the pressing force of the first pressing member 18a is 15N, and the pressing force of the second and third pressing members 18b and 18c is 7.5N.

  In this embodiment, as will be described in detail later, the first, second, and third pressing members 18a and 18b of the charger 12 are provided in order to improve the operability of the attachment / detachment operation (insertion / extraction operation) of the charger 12. , 18c (first, second, and third contact portions) are set as follows.

  First, the left shield plate 123a is provided with a first protrusion 19a, and the first pressing member 18a contacts the first protrusion 19a and presses the charger 12. The first protrusion 19a protrudes from the outer shape of the shield case 123 of the charger 12 formed by the left shield plate 123a on the side opposite to the pressing direction of the charger 12 by the first pressing member 18a. . The right shield plate 123b is provided with a second protrusion 19b, and the second pressing part 18b contacts the second protrusion 19b and presses the charger 12. The second protrusion 19b protrudes from the outer shape of the shield case 123 of the charger 12 formed by the right shield plate 123b on the opposite side to the pressing direction of the charger 12 by the second pressing member 18b. . That is, the contact positions of the charger 12 with the first and second pressing members 18a and 18b are charged by the first and second pressing members 18a and 18b with respect to the outer shape of the shield case 123 of the charger 12, respectively. It protrudes on the opposite side to the pressing direction of the vessel. In other words, the contact position of the charger 12 with the first and second pressing members 18a and 18b is retracted toward the left rail 16 and the right rail 17 with respect to the outer shape of the shield case 123 of the charger 12, respectively. Yes.

  Of the two pressing members 18b and 18c provided on the right rail 17, the third pressing member 18c on the rear side of the apparatus main body 2 is charged more than the second pressing member 18b on the front side. It is arranged at a position close to the container 12. That is, the charging position of the charger 12 with the second pressing member 18b is higher than the position of the charging apparatus 12 with the third pressing member 18c, and the charging device 12 by the second and third pressing members 18b and 18c. It protrudes on the opposite side to the pressing direction. In the present embodiment, the rear side of the apparatus main body 2 corresponds to the leading side in the insertion direction of the charger 12 into the mounting portion 3 as will be described later.

  Thus, in the present embodiment, the first pressing member 18a presses the left shield plate 123a via the first protrusion 19a. The second pressing member 18b presses the right shield plate 123b via the second protrusion 19b. Further, the third pressing member 18 c directly presses the left shield plate 123 b of the charger 12.

4). Next, the attaching / detaching operation (insertion / extraction operation) of the charger 12 in this embodiment will be described. FIG. 5 is a top view of the charger 2 and the mounting portion 3 for explaining the operation when the charger 12 is inserted into the mounting portion 3 of the apparatus main body 2.

  As shown in FIG. 5A, when the charger 12 is inserted into the mounting portion 3 of the apparatus body 2, the first and second pressing members 18a and 18b are in contact with the left and right shield plates 123a and 123b. It can be inserted smoothly. This is because the first and second pressing members 18a and 18b through which the leading side of the charger 12 passes when inserted into the mounting portion 3 are compared with the outer shape of the charger 12 formed by the left and right shield plates 123a and 123b. This is because they are retracted to the left and right rails 16 and 17, respectively.

  Then, as shown in FIG. 5B, the first and second pressing members 18a and 18b are respectively the first and second protrusions immediately before the charger 12 reaches a predetermined fixed position in the mounting portion 3. It begins to contact the parts 19a, 19b. At substantially the same time, the third pressing member 18c arranged on the rear side (the leading side in the insertion direction) of the apparatus main body 2 starts to come into contact with the outer shape of the charger 12 formed by the right shield plate 123b. .

  Finally, as shown in FIG. 5C, when the charger 12 reaches a predetermined fixing position in the mounting portion 3, all the pressing members 18a, 18b, 18c press and fix the charger 12.

  Thus, in this embodiment, the charger 12 can be inserted into and removed from the mounting portion 3 along the longitudinal direction of the charger 12. In the present embodiment, the first, second, and third pressing members 18 a, 18 b, and 18 c are provided on the mounting portion 3, and are elastically deformed by inserting the charger 12 into the mounting portion 3. The shield case 123 of the charger 12 is pressed by the elastic restoring force. Further, the third pressing member 18c is arranged on the leading side in the insertion direction of the charger 12 with respect to the second pressing means 18c. When the charger 12 is inserted into the mounting portion 3, the third pressing member 18 c is almost simultaneously with the first and second pressing members 18 a and 18 b starting to press the shield case 123 of the charger 12. It begins to press the shield case 123 of the charger 12.

  With such a configuration, an operator such as a user or a serviceman can clearly feel the pressing force immediately before the charger 12 reaches a predetermined fixed position when the charger 12 is inserted into the mounting portion. Therefore, erroneous work can be prevented.

5. As described above, according to the present embodiment, the charger 12 can be stably pressed and supported without hindering the movement of the cleaning members 124 and 127 that move in the charger 12. It is possible to suppress the vibration of the charger 12 that causes image damage. Further, when the charger 12 is inserted, a pressing feeling can be obtained immediately before the charger 12 reaches the predetermined fixed position, so that the operator can easily attach the charger 12 to the predetermined fixed position. It can be recognized and workability can be improved. Therefore, according to the present embodiment, the charger 12 can be stably supported while suppressing undesirable deformation.

Others While the present invention has been described with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

  In the above-described embodiments, the case where the corona discharger (corona discharge generator) is a charger that charges the surface of the photosensitive member has been described. However, the present invention is not limited to this. For example, the corona discharger is also used as a toner charging unit that charges the toner image on the image carrier before transfer, and a transfer residual toner charging unit that charges the transfer residual toner remaining on the image carrier after the transfer. . The corona discharger is also used as a static elimination unit that neutralizes the surface of the image carrier, a transfer unit that transfers a toner image from the image carrier to a transfer target, and the like. In these cases, the image carrier is not limited to the photoreceptor, and may be an intermediate transfer member. Even if the corona discharger is used for any of these applications, the same effect can be obtained by applying the present invention in the same manner.

  Moreover, in the above-mentioned Example, although the corona discharger was detachable with respect to the mounting part provided in the apparatus main body, it is not limited to this. For example, a process in which a photosensitive member and a process unit selected from the group including a charging unit, a developing unit, and a cleaning unit that act on the photosensitive unit are integrally formed into a cartridge and can be attached to and detached from the apparatus main body of the image forming apparatus. It may be a cartridge. Such a cartridge that can be attached to and detached from the apparatus main body of the image forming apparatus may include a mounting portion for the corona discharger according to the present invention, and the corona discharger according to the present invention may be attached to and detached from the mounting portion. Further, the corona discharger is not limited to a so-called replacement unit that is configured so that an operator such as a user or a serviceman can attach and detach relatively easily. The corona discharger may be one that is not normally attached / detached after being attached to the attachment part during manufacturing of the image forming apparatus or the like, except for repair.

DESCRIPTION OF SYMBOLS 3 Mounting part 11 Photosensitive drum 12 Charging device 16 Left rail 17 Right rail 18 Pressing member 100 Image forming apparatus 121 Grid 122 Discharge line 123 Shield plate 124 Cleaning pad 125 Cleaning pad holding member 127 Cleaning brush 128 Cleaning brush holding member

Claims (9)

In the image forming apparatus,
A photoreceptor,
A corona discharger for charging the photosensitive member, wherein a discharge electrode disposed along a longitudinal direction of the corona discharger and a first electrode disposed opposite to each other across the discharge electrode along the longitudinal direction A housing including one shield plate and a second shield plate and having an opening formed between the first shield plate and the second shield plate on one surface; and a portion to be cleaned of the corona discharger A cleaning member that cleans the portion to be cleaned by being moved while being in contact with the holding member, and a holding member that holds the cleaning member and is moved in the longitudinal direction, and is attached to and detached from the apparatus main body of the image forming apparatus Possible corona discharger,
The first shield plate is a mounting portion where the corona discharger is mounted with the opening facing the photoconductor, and the corona discharger is mounted at a charging position for charging the photoconductor. A first pressing member that presses the second shield plate toward the second shield plate, and the second shield plate is pressed toward the first shield plate in a state where the corona discharger is mounted at the charging position. A mounting portion having a second pressing member and a third pressing member,
Have
In the longitudinal direction, the first pressing member presses the first shield plate at each position where the second pressing member and the third pressing member press the second shield plate. An image forming apparatus, wherein the image forming apparatus is disposed at one end side position and the other end side position with respect to the position. The image forming apparatus according to claim 1, wherein the first pressing member presses the first shield plate at a substantially central portion in a longitudinal direction of the corona discharger. The second and third pressing members respectively press the second shield plate at a position that is substantially the same distance from the first pressing member in the longitudinal direction of the corona discharger. Item 3. The image forming apparatus according to Item 2. Wherein the cleaning section includes an image forming apparatus according to any one of claims 1 to 3, characterized in that said discharge electrodes. The corona discharger has a grid provided on the front Symbol opening, wherein the cleaning unit, the image forming according to any one of claims 1 to 3, characterized in that said grid apparatus. Before SL first pressing member, the second pressing member and the third pressing member, is elastically deformed by the front Symbol corona discharger is inserted into the mounting portion, said by its elastic restoring force The first pressing member presses the first shield plate, and the second pressing member and the third pressing member press the second shield plate . any image forming apparatus according to an item. When the corona discharger is inserted into the mounting portion, the first pressing member and the second pressing member start to press the first shield plate and the second shield plate, respectively . The image forming apparatus according to claim 6 , wherein the third pressing member starts pressing the second shield plate substantially simultaneously. Contact position between the first pressing member of the first shield plate is overhanging with respect to the outer shape of the front Symbol first shield plate, contact between the second pressing member of the second shield plate position the image forming apparatus according to claim 6 or 7, characterized in that protrudes with respect to the outer shape of the second shield plate. The contact position between the second pressing member of the second shield plate, wherein the second shielding plate 3 than the contact position between the pressing member, the by the second, third pressing member 9. The image forming apparatus according to claim 6 , wherein the image forming apparatus projects to a side opposite to a pressing direction of the second shield plate . 10.

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